Four years ago in a post titled “Dissent Out of Bounds on Uncommon Dissent (Oops, make that “Descent”)” I wrote of the banning of Elizabeth Liddle, a British neuroscientist whose nom de net is Febble, from Uncommon Descent (UD), the ID blog founded by William Dembski. That occurred during the reign of DaveScot as UD moderator, and resulted from DaveScot’s hissy fit about Liddle’s quite reasonable argument that Dembski’s definition of “intelligence” operationally made natural selection an intelligent process. Later DaveScot fell out of favor and was himself banned from UD.

Now under the reign of Barry Arrington, a lawyer, UD is engaged in a wholesale purge of commenters who are ID critics. At last rough count 20 commenters have been banned in the last couple of days, most of them ID critics. Once again, Lizzie (I’ve known her online for long enough to call her “Lizzie”!) is banned from UD. She wasn’t notified of it but (like other bannees) found she could no longer log in to UD. However, she has a new home, the The Skeptical Zone, to which I commend readers’ attention.

More below the fold

One of the reasons for the banning of a number of UD commenters seems to be failing Arrington’s litmus test concerning the law of non-contradiction

The existence of the LNC is the very basis of all argumentation, and anyone who denies it also denies meaning, order, truth and logic. For obvious reasons, therefore, it is not only useless but also affirmatively harmful to the search for truth to argue with someone who refuses to admit unambiguously the LNC. Arguing with a person who denies the basis for argument is self-defeating and can lead only to confusion. Only a fool or a charlatan denies the LNC, and this site will not be a platform from which fools and charlatans will be allowed to spew their noxious inanities.

For that reason, I am today announcing a new moderation policy at UD. At any time the moderator reserves the right to ask the following question to any person who would comment or continue to comment on this site: “Can the moon exist and not exist at the same time and in the same formal relation?” The answer to this question is either “yes” or “no.” If the person gives any answer other than the single word “no,” he or she will immediately be deemed not worth arguing with and therefore banned from this site.

We will start with Petrushka to demonstrate the application of the policy. Petrushka, can the moon exist and not exist at the same time and in the same formal relation?

Arrington’s snit apparently arose out of discussions of quantum mechanics in which some commenters speculated about whether quantum superposition–the fact that a quantum system can exist simultaneously in multiple states (see here)–could be generalized to macroscopic objects (see here and here for examples of those UD threads, if you have the fortitude to wade through them). That speculation is not necessarily pure moonshine. Quantum superposition has been observed in objects in the micron range.

I also accept the findings of physics which make the concept of physical existence rather complicated. That just means that physical is not the same as the ideal, just as a physical circle is not an ideal circle.

I thought this was something generally agreed upon. I thought it was the foundation of Plato’s thought.

But to answer the specific question, in formal logic, the moon cannot both exist and not exist.

The question faced by physics is somewhat different.

Seems reasonable, no? But appended to Petrushka’s comment is this:

UD Moderator: That’s not “no” Petrushka. Goodbye.

Other commenters were banned without notice, apparently including Febble, when they learned of their banning only when they found that they could no longer log in to UD.

This is of a piece with the main conflict resolution mechanisms available to religious movements: exclusion and suppression of dissenters. Arrington is creating an echo chamber inside of which ID proponents can talk sciency-sounding stuff to each other, safe from uncomfortable questions.

Watching the train wreck at UD reminds me of why I like the Bathroom Wall here on the Thumb. Lizzie has a related section called Guano, and The Secular Cafe has The Smoking Section and The Trashcan. Those seem to me to be preferable ways of handling obstropulous commenters and comments.